diff options
| author | Heiko Carstens <heiko.carstens@de.ibm.com> | 2014-03-10 14:50:16 +0100 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2014-03-17 15:53:06 +0100 |
| commit | cf813db0b448b45b454f0983329c3c7b007f9ab7 (patch) | |
| tree | 2ccbddbc0c1494d92e4fa4f1c2f7d337595e1dd2 | |
| parent | 36a554021b44d146178ae98e598c9502a1269f7d (diff) | |
s390/smp: limit number of cpus in possible cpu mask
Limit the number of bits to the maximum number of cpus a machine
can have.
possible_cpu_mask typically will have more bits set than a machine
may physically have. This results in wasted memory during per-cpu
memory allocations, if the possible mask contains more cpus than
physically possible for a given configuration.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| -rw-r--r-- | arch/s390/include/asm/sclp.h | 1 | ||||
| -rw-r--r-- | arch/s390/kernel/smp.c | 8 | ||||
| -rw-r--r-- | drivers/s390/char/sclp_early.c | 23 |
3 files changed, 26 insertions, 6 deletions
diff --git a/arch/s390/include/asm/sclp.h b/arch/s390/include/asm/sclp.h index abaca2275c7a..2f5e9932b4de 100644 --- a/arch/s390/include/asm/sclp.h +++ b/arch/s390/include/asm/sclp.h @@ -46,6 +46,7 @@ int sclp_cpu_configure(u8 cpu); int sclp_cpu_deconfigure(u8 cpu); unsigned long long sclp_get_rnmax(void); unsigned long long sclp_get_rzm(void); +unsigned int sclp_get_max_cpu(void); int sclp_sdias_blk_count(void); int sclp_sdias_copy(void *dest, int blk_num, int nr_blks); int sclp_chp_configure(struct chp_id chpid); diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c index a7125b62a9a6..8827883310dd 100644 --- a/arch/s390/kernel/smp.c +++ b/arch/s390/kernel/smp.c @@ -773,11 +773,11 @@ void __noreturn cpu_die(void) void __init smp_fill_possible_mask(void) { - unsigned int possible, cpu; + unsigned int possible, sclp, cpu; - possible = setup_possible_cpus; - if (!possible) - possible = MACHINE_IS_VM ? 64 : nr_cpu_ids; + sclp = sclp_get_max_cpu() ?: nr_cpu_ids; + possible = setup_possible_cpus ?: nr_cpu_ids; + possible = min(possible, sclp); for (cpu = 0; cpu < possible && cpu < nr_cpu_ids; cpu++) set_cpu_possible(cpu, true); } diff --git a/drivers/s390/char/sclp_early.c b/drivers/s390/char/sclp_early.c index 2c6aac66e2b0..14196ea0fdf3 100644 --- a/drivers/s390/char/sclp_early.c +++ b/drivers/s390/char/sclp_early.c @@ -20,7 +20,9 @@ struct read_info_sccb { struct sccb_header header; /* 0-7 */ u16 rnmax; /* 8-9 */ u8 rnsize; /* 10 */ - u8 _reserved0[24 - 11]; /* 11-15 */ + u8 _reserved0[16 - 11]; /* 11-15 */ + u16 ncpurl; /* 16-17 */ + u8 _reserved7[24 - 18]; /* 18-23 */ u8 loadparm[8]; /* 24-31 */ u8 _reserved1[48 - 32]; /* 32-47 */ u64 facilities; /* 48-55 */ @@ -32,13 +34,16 @@ struct read_info_sccb { u8 _reserved4[100 - 92]; /* 92-99 */ u32 rnsize2; /* 100-103 */ u64 rnmax2; /* 104-111 */ - u8 _reserved5[4096 - 112]; /* 112-4095 */ + u8 _reserved5[120 - 112]; /* 112-119 */ + u16 hcpua; /* 120-121 */ + u8 _reserved6[4096 - 122]; /* 122-4095 */ } __packed __aligned(PAGE_SIZE); static char sccb_early[PAGE_SIZE] __aligned(PAGE_SIZE) __initdata; static unsigned int sclp_con_has_vt220 __initdata; static unsigned int sclp_con_has_linemode __initdata; static unsigned long sclp_hsa_size; +static unsigned int sclp_max_cpu; static struct sclp_ipl_info sclp_ipl_info; u64 sclp_facilities; @@ -102,6 +107,15 @@ static void __init sclp_facilities_detect(struct read_info_sccb *sccb) sclp_rzm = sccb->rnsize ? sccb->rnsize : sccb->rnsize2; sclp_rzm <<= 20; + if (!sccb->hcpua) { + if (MACHINE_IS_VM) + sclp_max_cpu = 64; + else + sclp_max_cpu = sccb->ncpurl; + } else { + sclp_max_cpu = sccb->hcpua + 1; + } + /* Save IPL information */ sclp_ipl_info.is_valid = 1; if (sccb->flags & 0x2) @@ -129,6 +143,11 @@ unsigned long long sclp_get_rzm(void) return sclp_rzm; } +unsigned int sclp_get_max_cpu(void) +{ + return sclp_max_cpu; +} + /* * This function will be called after sclp_facilities_detect(), which gets * called from early.c code. The sclp_facilities_detect() function retrieves |